The **MPI5451R1-R33-R** is a high-performance, high-current power inductor manufactured by **Eaton (formerly Bussmann)**. It belongs to the MPI (Molded Powder Inductor) series, which is specifically designed for high-density power applications. --- ### 1. Key Technical Specifications | Parameter | Value | | :--- | :--- | | **Inductance** | 0.33 µH | | **Tolerance** | ±20% | | **Current Rating (Irms)** | 18.0 Amps | | **Saturation Current (Isat)** | 32.0 Amps | | **DC Resistance (DCR)** | 2.1 mΩ (Typical) | | **Operating Temperature** | -40°C to +125°C | | **Package / Case** | 5.4mm x 5.1mm x 1.2mm (SMD) | --- ### 2. Core Features and Construction * **Molded Powder Technology:** The inductor uses a composite iron powder material. This construction allows for high current handling capabilities and a "soft" saturation characteristic (where inductance drops gradually rather than abruptly as current increases). * **Magnetically Shielded:** The molded design inherently provides magnetic shielding, which minimizes Electromagnetic Interference (EMI) with surrounding components on the PCB. * **Low Profile:** With a height of only 1.2mm, it is ideal for ultra-thin electronic devices. * **Low DCR:** The very low DC resistance (2.1 mΩ) minimizes power loss and heat generation, increasing the overall efficiency of the power supply. --- ### 3. Part Number Breakdown Understanding the nomenclature helps in identifying variants: * **MPI:** Series Name (Molded Power Inductor). * **5451:** Physical Dimensions (approx. 5.4mm x 5.1mm). * **R1:** Height code (1.2mm). * **R33:** Inductance value (R33 = 0.33 µH). * **-R:** RoHS compliant. --- ### 4. Typical Applications Because of its high current density and low profile, this part is commonly found in: 1. **Voltage Regulator Modules (VRMs):** Used in laptops and servers. 2. **DC-DC Converters:** Point-of-load (POL) converters for CPUs and GPUs. 3. **Handheld Devices:** Smartphones and tablets where board space and height are restricted. 4. **Battery Powered Systems:** Where high efficiency is critical for battery life. ---